THE THIGH.
93.Poupart’s ligament, or crural arch.—Mark the anterior superior spine of the ilium, the spine of the pubes, and define the line of ‘Poupart’s ligament’ which extends between them. This line is one of our guides in the diagnosis of inguinal and femoral herniæ. If the bulk of the tumour be above the line, the hernia is probably inguinal; if below it, femoral. The line is not a straight one drawn from the spine of the ilium to the spine of the pubes, but slightly curved, with the convexity downwards, owing to its close connection with the fascia lata of the thigh. In many persons it can be distinctly felt; in nearly all its precise course is indicated by a slight furrow in the skin.
For the points about the spine of the pubes, refer to paragraph69.
94.Furrow at the bend of the thigh.—When the thigh is even slightly bent, there appears a second furrow in the skin below that at the crural arch. This secondfurrow begins at the angle between the scrotum and the thigh, passes outwards, and is gradually lost between the top of the trochanter and the anterior superior spine of the ilium. It runs right across the front of the capsule of the hip-joint. For this reason it is a valuable landmark in amputation at the hip-joint. The point of the knife should be introduced externally where the furrow begins, should run precisely along the line of it, and come out where it ends; so that the capsule of the joint may be opened with the first thrust. In suspected disease of the hip pressure made in this line, just below the spine of the ilium, will tell us if the joint be tender. Effusion into the joint obliterates all trace of the furrow, and makes a fulness when contrasted with the opposite groin.
95.Saphenous opening.—In most persons there is a natural depression over the saphenous opening in the fascia lata, where the saphena vein joins the femoral. The position of this opening is just below the inner third of Poupart’s ligament, and about an inch and a half external to the spine of the pubes. This is the place where the swelling of a femoral hernia first appears: therefore it ought to be carefully examined in cases of doubt.
96.Femoral ring.—The position of the femoral ring, through which the hernia escapes from the abdomen, is on a deeper plane, about half an inch higher than the saphenous opening, and immediately under Poupart’s ligament. As the plane of the ring is vertical in the supine position of the body, the way in which we should try to reduce a femoral hernia is by pressure, applied first in a downward direction, afterwards in an upward. The intestine protruded has to pass back under a sharp edge of fascia, namely, the upper horn of the saphenous opening (known as Hey’s ligament). At the same time we bend the thigh, to relax the fascia as much as possible.
A good way to find the seat of the femoral ring with precision is the following:—Feel for the pulsation of the femoral artery on the pubes; allow half an inch (on the inner side) for the femoral vein; then comes the femoral ring.
In performing the operation for the relief of the stricture in femoral hernia the incision through the skin should be about an inch and a half external to the spine of the pubes. Its direction should be vertical, and its middle should be just over the femoral ring.
97.Lymphatic glands in the groin.—The cluster of inguinal and femoral lymphatic glands can sometimes be felt in thin persons. The inguinal lie for the most part along the line of Poupart’s ligament: they receive the absorbents from the wall of the abdomen, the urethra, the penis, the scrotum, and the anus. The femoral glands lie chiefly over the saphenous opening and along the outer side of the saphena vein: they receive the absorbents of the lower extremity; they receive some also from the scrotum—of which we have practical evidence in cases of chimney-sweepers’ cancer.
98.Trochanter major.—The trochanter major is a most valuable landmark, to which we are continually appealing in injuries and diseases of the lower extremity. There is a natural depression over the hip (in fat persons) where it lies very near the surface, and can be plainly felt, especially when the thigh is rotated. Nothing intervenes between the bone and the skin except the strong fascia of the gluteus maximus and the great bursa underneath it.
The top of the trochanter lies pretty nearly on a level with the spine of the pubes, and is about three-fourths of an inch lower than the top of the head of the femur. A careful examination of the bearing of the great trochanter to the other bony prominences of the pelvis, and a comparison of its relative position with that of the opposite side, are the best guides in the diagnosis of injuries about the hip, and the position of the head of the femur.
99.Nélaton’s line.—‘If in the normal state you examine the relations of the great trochanter to the other bony prominences of the pelvis, you will find that the top of the trochanter corresponds to a line drawn from the anterior superior spine of the ilium to the most prominent part of the tuberosity of the ischium. This line also runs through the centre of the acetabulum. The extent of displacement indislocation or fracture is marked by the projection of the trochanter behind and above this line.’[7]
‘Nélaton’s line,’ as it is termed, theoretically holds good. But in stout persons it is not always easy to feel these bony points so as to draw the line with precision. A surgeon must, after all, in many cases trust to measurement by his eyes and his flat hands—his best guides. Thus, let the thumbs be placed firmly on the spines of the ilia, while the fingers grasp the trochanters on each side. Having the sound side as a standard of comparison, the hand will easily detect any displacement on the injured side. Hippocrates bids us compare the sound parts with the parts affected (in fractures) and observe the inequalities.
The top of the great trochanter is the guide in an operation recently introduced byMr.Adams, namely, the ‘subcutaneous section of the neck of the femur.’ ‘The puncture should be made one inch above and nearly one inch in front of the top of the trochanter. The neck of the bone is to be sawn through at right angles to its axis, the saw working parallel to Poupart’s ligament, and about one inch below it.’
Spine of the ilium.—The anterior superior spine of the ilium is the point from which we measure the length of the lower limb. By looking at the spines of opposite sides we can detect any slant in the pelvis. By pressure on both spines simultaneously we examine if there be a fracture of the pelvis, or disease at the sacro-iliac joint.
100. ‘In reducing a dislocation of the hip by manipulation it is important to bear in mind that, in every position, the head of the femur faces nearly in the direction of the inner aspect of its internal condyle.’[8]
101.Compression of femoral artery.—About a point midway between the spine of the ilium and the symphysis pubis, the femoral artery can be felt beating, and effectually compressed, against the pubes. How should the pressure be applied when the patient lies on the back? In accordance with the slope of the bone—that is, with a slight inclination upwards. A want of attention to this point is the reason why so many fail when they undertake to command the circulationthrough the femoral artery in an amputation, or to cure an aneurysm by digital compression.
If the Italian tourniquet be used, we should be careful to adjust the counter-pad well under the tuberosity of the ischium. If digital pressure be used, it is easy to command the femoral by slight pressure of the thumb, provided the fingers have a firm hold on the great trochanter.
102.Sartorius.—The sartorius is the great fleshy landmark of the thigh, as the biceps is of the arm, and the sterno-cleido-mastoideus of the neck. Its direction and borders may easily be traced by asking the patient to raise his leg, a movement which puts the muscle in action. The same action defines the boundaries of the triangle (of Scarpa) formed by Poupart’s ligament, the adductor longus and sartorius.
Line of femoral artery.—To define the course of the femoral artery, draw a line from midway between the anterior superior spine of the ilium and the symphysis pubis to the (spur-like) tubercle for the adductor magnus on the inner side of the knee. The femoral artery lies under the upper 2/3 of this line.
The sartorius begins to cross the artery, as a rule, from three to four inches below Poupart’s ligament. The point at which the profunda artery arises is about one and a half or two inches below the ligament. Therefore the incision for tying the femoral in Scarpa’s triangle should commence about a hand’s breadth below Poupart’s ligament, and be continued for three inches in the line of the artery.
To command the femoral in Scarpa’s triangle, the pad of the tourniquet should be placed at the apex, and the direction of the pressure should be, not backwards, but outwards, so that the artery may be compressed against the femur.
In the middle third of the thigh the femoral artery lies in Hunter’s canal, overlapped by the sartorius. About the commencement of the lower third the artery leaves the canal through the oval opening in the adductor magnus, and, under the name of popliteal, enters the popliteal space. The line for finding the artery in Hunter’s canal has been already traced(102). The incision to reach the artery in this part of its course would fall in with the outer border of the sartorius.
To command the femoral artery in Hunter’s canal, the pressure should be directed outwardly, so as to press the vessel against the bone.